Boilers for power plants



56] References Cited L'NITED STATES PATENTS IDHJRIOT James H. Anderson 1615 Hilloek Lane. York. Pennsylvania XX 1 l1. 1 7 WW k mm w A r. nu b HAWK mm m H.SE "L d mm m k m r rd Be on nm \A l ca KP. 36 n 99 MO M .mm 4. e K I) on. 40 M +0 mm .16 mm n 3.3 PA 9 m 9 .19 1 36 4 3 m no oo-MO u s m d. wh .la AFP. N 7.7.4

[54] BOILERS FOR POWER PLANTS 5 Claims, 2 Drawing Figs.

12235 ABSTRACT: A heat sponge and safety vapor flow rcturder FZZb 37/22 structure is disclosed which is housed within the vapor dome 60/3918; of a boiler in u boilcr-turbinc-condenser type power plant 122/1 l 35 which uses a halocarbon as the working fluid.

[51] int. {50] Field [liliHHHPii FIGI FRI-:21

L- I il I INVENTOR JAMES H. ANDERSON Patented Oct. 13, 1970 ATTORNEYS BOILERS FOR POWER PLANTS BACKGROUND OF THE INVENTION In adopting the principles of boiler-turbine-condenser type power plants for use as prime movers on automobiles. it is well knownthat the usual operating conditions for an automobile require surges of excess power for acceleration, for example, for passing other vehicles. Conventionally, with internal combustion engines the problem is generally solved by overpowering, that is, installing an engine with a higher horsepower rating than is otherwise necessary to operate the automobile. In my prior U.S. Pat. No. 3,260,050 of July 12. I966, one embodiment of a turbine power plant adapted for automotive use is disclosed. One advantage of that type of power plant for automotive use is that heat energy is stored in the high pressure superheated vapor in the dome 40 shown in FIG. 2 of the above-mentioned patent. Under conditions of stable power requirements, the heat supplied by the burner boils enough liquid into vapor to maintain constant pressure and temperature conditions throughout the system. Under conditions of sudden high demand, however, as when the turbine nozzles are suddenly opened, the pressure and temperature within the vapor dome may drop more rapidly than the capacity of the boiler to maintain a given temperature and pressure. By the same token, the heat rejected by the condenser to the sur rounding atmosphere or other heat exchange fluid must be maintained in balance with the heat input from the turbine exhaust. Whenever the flow from the boiler is suddenly increased under conditions of rapid acceleration of the vehicle, for example, then the equilibrium of the entire system is upset due to the fact that the burner cannot instantaneously supply enough heat to maintain the system in balance at the suddenly higher flow rates.

Obviously there is a practical limit to the size that the vapor dome can take and therefore a practical limit on the amount of heat that can be stored in superheated vapor within the vapor dome. The larger the storage dome is, the slower will be the rate of drop of temperature of the vapor in response to increased load on the turbine. For each drop in temperature of the vapor within the dome, there is an increase in the temperature differential between the walls of the boiler and the vapor and the rate of heat exchange between the two therefore increases. It is apparent therefore that the metal comprising the boiler wall also functions as a heat storage device to supply heat and to vaporize liquid at a greater rate than normal under conditions of abnormal vapor demand.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS F IG. 1 is a partial side elevation partially in section showing a boiler and vapor dome in accordance with the present invention and with a heat sponge contained within the vapor dome; and

FIG. 2 is a view on the lines 2-2 of FIG. 1 showing a preferred embodiment of the heat sponge structure.

DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 is taken substantially from FIG. 2 of my aforementioned patent and reference may be had to that patent for description of the structure and operation of the rotary boiler.

While installation of a heat sponge in accordance with the present invention may require some minor adjustment of the standpipe structure and valving arrangement shown within the vapor dome, it is contemplated that the overall operation of the boiler will not be altered materially'except that the heat storage capacity of the vapor dome will be vastly increased.

A few simple thermodynamic computations will show that in the case of iron. the heat released per cubic foot per degree Fahrenheit would equal 65.5 B.t.u. at 500 F. For aluminum at the same temperature. the heat released would be 34 B.t.u. For beryllium at the same temperature the heat released per unit volume would be 58 B.t.u. While the foregoing examples are not intended to be in any way all inclusive, it is apparent from a consideration of these three metals that iron has the highest heat storage capacity per unit volume, but the lowest per pound. Beryllium. on the other hand, has the highest heat storage capacity per pound. and slightly less than iron per unit volume. Comparing the above figures with the heat storage capacity of a typical vapor useful in turbines of the type to which the present invention is addressed such as CF -,CH- Cl, the figures are very much higher as the heat energy given up per unit volume of vapor would be of the order of .740 B.t.u. per cubic foot per degree Fahrenheit. Although the energy storage per pound is greater for the vapor than for iron, it is less than aluminum or beryllium and the energy storage per unit volume is far less than any of the metals considered. For a given mass, aluminum stores approximately 22 percent more energy and for a given volume 46 times as much energy as the vapor. If follows therefore that the heat storage capacity of a vapor dome can be greatly increased by largely filling the space within the dome with metal having a high heat storage capacity. However, a solid block of metal would not suffice for this purpose because of the time element involved for release of the stored heat energy to the vapor. The time required is directly proportional to metal thickness through which the heat must flow and inversely proportional to the area in contact with the vapor. Ideally, therefore, the ratio of area to volume should be as large as possible for optimum performance. This suggests that the heat sponge should be formed of metal in the form of thin sheets, wires, tubes, granules or a porous mass.

As indicated in FIG. I, the heat sponge may conveniently take the form of a stack of annular plate members 42 which substantially fill the interior of the dome 40 between the vapor outlet standpipe and the interior walls of the dome. A preferred form of the sponge is detailed in FIG. 2 showing that the annular plates 42 are separated by corrugated plates 44 which hold the plates in substantially parallel relationship to each other and at the same time provide a plurality of restricted paths of flow for the vapor. i

The sturcture shown in FIGS. 1 and 2, while approaching the optimum for rate of heat storage and heat transfer, also has a further advantage. The plurality of somewhat restricted fluid passageways which are defined by the corrugated and flat plates provides a safety factor for the operation of apparatus of this type. In the event of rupture of either the vapor dome or the boiler, the violence of any resulting explosion is greatly decreased by the heat sponge of the present invention because it slows up the release of vapor to either the interior of the boiler or to the atmosphere. Under normal conditions of operation of the power plant, the pressure drop through the heat sponge is insignificant but in the event of rupture of the vapor dome or the boiler the pressure drop becomes substantial and therefore greatly reduces the time rate of release of the vapor to the atmosphere and thereby reduces the violence of any explosion which would otherwise occur in the event that vapor within the dome were free to expand immediately upon rupture of the surrounding vessel.

Iclaim:

1. In a power plant of the boiler-expansion engine-condenser type in which the boiler includes a vapor chamber having a vapor outlet leading to the inlet of the turbine, a high capacity heat sponge positioned within said vapor chamber comprising: a mass of metal substantially filling the space within the vapor dome, having a high ratio of surface area to volume and further having a configuration defining a plurality of restricted vapor flow passageways for retarding the release of vapor in the event ofrupture of the boiler or chamber wall.

2. In a power plant of the boiler-expansion engine-condenser type in which the boiler includes a vapor chamber having a vapor outlet leading to the inlet of the turbine. a high capacity heat sponge positioned within said vapor chamber comprising:

a. a plurality of substantially flat metallic plate-like members; and

b. a plurality of corrugated metallic members separating said plate-like members and maintaining them in su bstantially parallel relation. said members substantially filling the space within said vapor chamber and defining a plurality of restricted vapor flow passageways which retard the release of vapor in the event of rupture of the boiler or chamber wall.

3. Apparatus as defined by claim 2 in which said heat LII sponge members are formed of a metal selected from the group consisting of iron. aluminum and beryllium.

4. Apparatus as defined in claim 2 in which said heat sponge members are formed of the same metal.

5. In a power plant of the b0ilertu rbine-condenser type in which the boiler includes a vapor dome surrounding a vapor exhaust standpipe. a high capacity heat sponge positioned between said standpipe and said vapor dome comprising:

a. a plurality of substantially annular flat metallic plate-like members; and

b. a plurality of corrugated metallic members separating said plate-like members and maintaining them in substantially parallel relation. said members substantially filling the space between said standpipe and vapor dome and defining a plurality of restricted vapor flow passageways which retard the release of vapor in the event of rupture of the boiler or dome. 

